What's beef? Beef is staring down your mouthy rival in the ready room as he dances around like Apollo Creed in a bizarre, futile attempt to psych out the world's greatest swimmer.

That's what Michael Phelps did to Chad Le Clos on Monday night while they were waiting for the start of their 200 butterfly race. It was their first showdown in the event since 2012, when Le Clos stunned the world by knocking off Phelps in his signature event by 0.05 seconds to win gold and deliver Phelps to a shocking silver. With that four-year-old win under his belt, Le Clos was dancing, shadowboxing and staring down the guy he beat once and the guy who has 18 more gold medals than him. In addition to all the ready-room histrionics, Le Clos kept his eyes on Phelps when they went out to the blocks. While he kept leering at Phelps, who looked completely unaware of the one-man stare down, Le Clos dramatically ripped off his jacket, like the jukebox had just stopped at the malt shop and he was looking to have a little scrap before The Fonz broke it up. The whole thing was bizarre.

Le Clos has been mouthy ever since he touched the wall first in that London race. At first, you could understand. You topple the king, you're entitled to some boasting. But things escalated last year when Phelps returned to the pool and commented that the butterfly times in his retirement absence had been lackluster. So, a few months later, Le Clos went out, won the world championships with a fast time and basically said "take that, Michael." Then, hours later, Phelps bested that time in another meet.

Phelps won Monday's race and afterward said he wasn't looking at Le Clos. "He does his thing, I do my thing."

But the greatest part of Monday's beef was that it took place before a semifinal! It'd be like Apollo dancing before that "ding, ding" sparring bout with Rocky at the end of Rocky III.